In order to accomplish market needs in glass industry and be able to produce glass containers at competitive prices, high manufacturing rates are required. As a consequence, molds are being submitted to shorter and shorter thermal cycles leading to higher mechanical stresses and, in some cases, to plastic deformation. Therefore, fatigue, oxidation, corrosion, cracking, wear and demolding problems are often occurring inducing premature failure of the molds during service. Furthermore, these problems are responsible for the instability of the production process, the low quality of the manufactured parts and the increase of the maintenance costs. In order to prevent the premature occurrence of such problems, molds have been: (i) manufactured with high thermal conductivity materials, further improved by channels and fins cooled by compressed air; (ii) coated with high temperature thermal and mechanical resistant materials and, (iii) lubricated (with liquid lubricants) to allow the easy demolding operation. Although successful improvements have been achieved in the lifetime and production rates of the molds, the above described problems are constantly updated due to either the increasing mechanical loading, to which molds and coatings are submitted, or the use of liquid lubricants inducing molding corrosion and leading to a deficient demolding and defective parts with incorporated debris.
This project aims to select and develop a new range of materials which will allow to overcome molds problems in glass industry, promoted by either harsh service conditions and liquid lubricants use. The objectives are focused on the simultaneous increase of the lifetime and production rates as well as on the decrease of the maintenance costs. Three research lines are proposed for completing these objectives, as follows:
(i) firstly, based on the intense development of copper-based metallic alloys in last years, replacement of the high thermal conductivity alloys, presently used in molds manufacturing, by state of the art ones with better mechanical and thermal properties is proposed;
(ii) secondly, a new mold concept based on bulk materials with better mechanical and thermal properties, associating self lubrication, will be developed. The purpose is to develop composite materials, incorporating nanocrystalline diamond, to be applied as a shell on the mold body manufactured with the alloys studied in the previous research line.
(iii) finally, the third line of research is focused on the application of a new class of hard coatings with high temperature self-lubricant properties, sputter deposited onto the molding surfaces of the molds manufactured with the alloys previously developed.
The first solution is to have outputs in the short term whereas the other two show a radical innovation change which can contribute to significantly improve the performance of the industrial partners, not only at short but at medium and long terms. The industrial success of the application of these materials allows forecasting important productivity and agility gains which are fundamental for the improvement of the companies’ international competitiveness, either on the production of glass containers or on the manufacturing of molds for the glass industry.